1. Field of the Invention
The present invention relates to a door glass run for a motor vehicle.
2. Description of the Prior Art
As shown in FIG. 4, a door glass run 4 is attached to an inner periphery of a door sash 2 of a door 1 of a motor vehicle for guiding a door glass 3 to its closed and open positions, and sealing a gap between a peripheral edge of a door glass 3 and the door sash 2 when the door glass 3 is fully closed.
As shown in FIGS. 5 and 6, the door glass run 4(hereinafter will be merely called glass run) is provided with a base portion 41 having a U-shaped cross-section and lips 44, 45 formed at open ends of the base portion 41 for holding the periphery of the door glass 3. The door sash 2 has a channel portion having a U-shaped cross-section in its inner peripheral portion. The base portion 41 of the glass run 4 is fitted to the channel portion of the door sash 2.
The glass run 4 is generally composed of an extruded lateral member 4A to be attached along a lateral frame portion of the door sash 2, an extruded vertical member 4B to be attached along a vertical frame portion of the door sash 2 and a molded corner portion 4C to be attached along a corner portion C of the door sash 2(FIG. 4). The molded corner portion 4C connects the lateral member 4A to the vertical member 4B(U.S. Pat. No. 4,977,706).
The lateral member 4A is generally provided with a tubular seal portion 40. When the door glass 3 is fully closed, a seal wall 46 of the tubular seal portion 40 is pushed upwardly by the peripheral edge of the door glass 3.
As shown in FIG. 6, the molded corner portion 4C is provided with a tubular seal portion 40' which is continuous with the tubular seal portion 40 of the lateral member 4A. One end of the seal wall 46' of the tubular seal portion 40' is connected to the seal wall 46 of the lateral member 4A while the other end thereof is connected to a lower end portion of a vertically extending bottom wall of a base portion 41' of the molded corner portion 4C.
The lateral member 4A is connected to the vertical member 4B with the molded corner portion 4C in the following manner. Ends of the members 4A, 4B are placed at both ends of a cavity of a mold so as to face in nearly perpendicular relation to each other, a core for molding the tubular seal portion 40' is inserted in the cavity, and a molding material is injected into the cavity. The resulting corner portion 4C has an opening 47 for removing the core from the tubular seal portion 40'. When the glass run having the molded corner portion 4C is attached to the door 1, the opening 47 is covered with the door sash 2 so as to be concealed from an external view of the motor vehicle.
However, due to the opening 47, the rigidity of the molded corner portion 4C decreases. This causes the corner portion 4C to be irregularly deformed when fitted to the door sash 2. As a result, the corner portion 4C is likely to be offset from a predetermined assembly position, which thereby reduces the sealing properties of the seal wall 46' against the door glass 3.
On the other hand, the assembled positions of the door glass can vary upwards or downwards. In a conventional glass run as shown in FIGS. 5 and 6, when the seal wall 46' is pushed excessively upwards by the fully closed door glass 3 that is assembled at an upwardly offset position, the lip 44 is easily deformed due to a lack of rigidity of the corner portion 4C. This causes the appearance around the molded corner portion 4C to be deteriorated.